This invention generally relates to an electrical junction box containing electrical wiring junctions that are isolated from a harmful electrical equipment enclosure, such as a wet well pumping system that produces contaminants and, more particularly, to a method of installing and servicing the box.
An electrical junction box is a wiring interface container that contains electrical wiring junctions or connections between wire runs from electrical equipment or outlets in an equipment enclosure, such as a home or like structure, and a main power supply provided by a local utility or a control panel. One purpose of the junction box is to conceal the electrical junctions from sight, which is more esthetically pleasing than a bunch of exposed electrical wires connected together. While it is true that the junction box presents a neater means of concealing the electrical junctions, the real value of the box is in providing a degree of protection for the wiring interface at the various junctions. The junction box can also help contain electrical sparks in the event that one of the junctions overloads for some reason, and thus limits the amount of damage that is caused by electrical sparking. The junction box may include a safety switch that allows the connections made within the box to be shut down in an emergency. An openable door on the box allows access by service personnel to the junctions.
Occasionally, system maintenance, replacements, upgrades and like service of the electrical equipment or the wiring within a particular equipment enclosure will dictate the installation of a larger or a new junction box to accommodate additional electrical junctions, or additional or larger electrical cables. In the event that the equipment enclosure contains harmful contaminants, as described below, such contaminants must be contained to prevent damage to other electrical devices and to prevent migration to occupied places.
One well-known example of a harmful equipment enclosure is a wet well pumping system for pumping waste water such as sewage, including liquid and solid waste, from community structures, such as domestic residences, office buildings, companies, industries, farms, institutions, and the like, to sewage or drainage pipes for treatment in a sewage treatment plant prior to safe, sanitary discharge. The sewage is typically collected in a wet well, which may be below or above ground. In a typical multi-story, office building application, the wet well is located below street level in the basement of the building and collects sewage from each floor, and the pumping system pumps the collected sewage back up to a street sewage pipe at a higher elevation. A typical pumping system includes one or more submersible electrical pumps in the wet well and connected to discharge pipes that extend generally upwardly from inside the well, through a cover overlying the well, and outside the well to the street sewage pipe. An electrical probe inside the well detects the level of waste water in the well to control the actuation of the pumps. Electrical wire runs are routed from the pumps and the probe inside the well to an electrical junction box located in the immediate vicinity outside the well. The junction box is, in turn, connected to a remote control panel that, in turn, is connected to a mains power supply.
Poisonous and noxious gases, odors and like contaminants can accumulate within the well and migrate to the junction box and, in turn, to the control panel, and beyond, to occupied places, such as offices, living spaces, mechanical rooms, etc., thereby exposing occupants and personnel to the noxious gases, odors, and contaminants accumulated therein. These contaminants can severely damage wiring and electrical devices, such as relays, electrical circuits, circuit breakers, terminal connections, connectors, etc.